You will find a lot of odd fish mixes on Youtube. They usually don't state that the fish are all juvenile (hence will survive a few months) or were not in there long before one half ate the other half etc

question:how long should i cycle my tank for before adding fish?and secondly, how many fish can i put in the tank at once? with marine you can only do something like 2 but the place i am buying the fish from said 10 would be ok for a 125litre tank. is this correct?

Depends on size. Volume is also not as good as surface area when it comes to working out stocking.I always suggest 4 neon sized fish in a 2ft tank (talking standard tank sizing here eg 2ft x 1 x 1 etc), 6 in a 3ft, 8 in a 4ft.

thanks for that. so do i need to wait for nitrates to go down? meaning the cycle is pretty much finished and then add fish? as the lfs said to add something like fresh start to get the cycle going which we did. and he said something about the cycle being less as it say you can add fish 3 days later which we havent done as i dont see how something that takes a good few weeks to cycle only taking 3 days.

Your nitrates will depend a lot on the local water supply you are using. Some supplies are high in nitrates so there is not a lot you can do, except have a lot of fast growing plants.Are you cycling with fish or without? If without, you need an ammonia source or all you are doing is letting the tank sit with a bit of Fresh Start stuff in it. It will not cycle like this.

got my new fish today, and i cant believe how well they have settled already, within 5 mins they were feeding on the plants and swimming around as though they have lived in here for years. no fighting which is weird after marines, much prefer this lol